We only officially support using our software with PHP 5.6, 7.1, 7.2 or 7.3. We strongly advise you to run the latest available version of PHP on a branch currently maintained by the PHP project for security and performance reasons. Older versions of PHP have known major security issues which are being actively exploited to hack sites and they have stopped receiving security updates, leaving you exposed to these issues. Moreover, they are slower, therefore consuming more server resources to perform the same tasks.
Kindly note that our policy is to officially support only the PHP versions which are not yet End Of Life per the official PHP project with a voluntarily extension of support for 6 to 9 months after they become End of Life. After that time we stop providing any support for these obsolete versions of PHP without any further notice.